Its true that some people can not be deterred by others with firearms, those people clearly have a death wish, but the vast majority would most likely be deterred, which is why they tend to attack places in which guns are not allowed. I can't say much about the firearm laws of Canada but I do know they are a lot more strict than here in the US, mainly because every state here has their own laws. the question is, how do you stop someone from committing a shooting in general? the problem isn't what firearm they use, or that they are using a firearm, its how do we protect those who can't protect themselves from those who desire to harm them?
Police response times are slow, and politics and fear tactics get in the way of logical thought. The emotional jump the gun to ban the guns is a poor response to these crimes that happen. we have more armed guards on our politicians than we do on our children, the future of the world.
Education is key. I do believe adults should be more educated about firearms before they should be able to own one and require education to their children of those that own firearms. I can say first hand that kids educated about firearms are less likely to accidents and also a lot less likely to want to play with them.
I think that a part of whats wrong with society today is that kids parents don't play as much of a part in their kids life as they used to.